Ultra-violet lamp and system



March 31, 1931. P. H. CRAIG ULTRA VIOLET LAMP AND SYSTEM Filed April 18, 1929 fainter/f 07-4 WW ii Patented Mar. 31, 1931 UNITED STATES PALMER H. CRAIG, OF CIN'CHQ'NATI, OHIO ULTRA-VIOLET LAMP AN D SYSTEM.

Application filed April 18, 1929. Serial No. 856,211.

A further object of my invention is to devise a system for ener izing my ultra-violet lam iin which there is incorporated an infrared eater which serves a dual purpose of emitting infra-red rays and acting as a resistance in the circuit of the ultra-violet lariip y invention is illustrated in the accompanying drawing in which:

Figure 1 shows my improvedultra-violet lamp and the infra-red heater in proper operatmg position in the system; and

Figure 2 is a perspective view of the elec- {rode arrangement within my ultra-violet amp.

Referring to Figure 1, my ultra-violet lamp comprises an envelope 1 made of quartz or other material, such as Corex glass, which is transparent to ultra-violet radiations. Sealed within the envelope is a stem 2 of suitable material having sealed therein two electrodes 3 and 4. These electrodes are sealed to the stem 2 by means of suitable sealin -in sections 3a and 4a embedded in the pmch 2a. 3b and 46 indicate the lead wires for electrodes 3 and 4 respectively. The stem 2 is rovided with a tubular extension 2" exten ing from a point on one side of the stem above the pinch 2a to a point be yond the ends of electrodes 3 and 4.- An electrode 5 is sealed into the end of tubular extension 2?) b a sealing-in wire section 5a, and is provi ed with a lead-in conductor 56. As will be seen from Figure 2, electrode 5a is bent so the end of the electrode lies in the plane of electrodes 3 and 4, and is equispaced from these latter electrodes. The extension 26 serves both as a mechanical support for electrode 5 and as an insulating covering for the lead wire to the electrode 5 to prevent discharge between this wire and electrodes 3 and 4. A short length of tungsten wire A is connected between electrodes 3 and 4 at a point near the pinch 2a. This wire constitutes a filament, and is adapted to be heated to incandescence by current passing through it, as will be explained hereinafter. Envelope 1 is provided with an ordinary screw plug connector cooperating with one socket 6a of a double socket element 6. The leading-in wires 3?) and 4b of electrodes 3 and 4 are connected respectively to the button and shell of the plug connector on the envelope 1. The leading-in conductor 56 for electrode 5 is connected to a metallic annular shell 7 mounted upon envelope 1 concentric \fmth the plug connector but insulated thererom.

The double socket connector 6 is provided with sockets 6a and 6b and a screw plug 60. The shell of screw plug 60 is connected to the center contact of socket 6a by means of a conductor 6d. The shell of socket 611 is connected to the shell of socket 66 by conductor 60, and the center contact button of screw plug 60 is connected to the center contact of socket 612 by conductor 6d. Between sockets 6a and 6b is located a suitable resistance 8 which is connected to the center contact of screw plug 60 by conductor- 8a, and is connected at the other terminal to metallic ring 7 by a sprin contact finger 86. As will be seen from igure 1, resistance element 8 is connected in series with electrode 5 of the ultra-violet lamp and serves as a ballast resistance to properly regulate the operation of the lamp. For operation on ordinary house lighting systems (110-120 volts) this resistance is of the order of ohms.

An infra-red heater unit 9 is supported -within socket 6?) by means of an ordinary screw plug connector, and comprises a core 9a of lava or other suitable heat resisting insulating material, and a suitable resistance wire 9?; wound around the core 9a. 'One end of the wire is connected to the shell of the screw plug while the other end is connected to the center contact button of the plug. The infra-red heater unit may be of the type ordinarily used in commercial infrared heaters, or the heater unit may comprise a carbon filament lamp of the type now chtainable on the market for thera eutic urposes. The only requirement is t at it. ave a proper resistance to limit the current flowing through the filament A of the ultra-violet lamp. It will be understood of course, that the filament A and the heater unit 9 are properly designed so that the heater unit 9 will function both as a limiting resistance for the current flowin through filament A and as an emitter of ini ra-red radiations.

In the manufacture of my ultra-violet lamp, a small drop of mercury indicated at 10 is inserted into the envelope 1 before evacuation. During evacuation the lamp is heated externally to drive out residual gases,--and the filament A is kept burning. The lamp is evacuated to a pressure of the order of 1.5 or 2.0 mm. of mercury. V

In the operation of my ultra-violet lamp the heating filament A serves to ionize the mercury vapor within the lamp and thereby permits an electric discharge between electrodes 5 and electrodes 3 and 4. This discharge occurs principally between the tips of electrodes 3 and 4 and the electrode 5, and is rich in ultra-violet radiations. The infra-red heater unit 9 emits infra-red rays which are beneficial for therapeutic purposes, and both the heater and the ultra-violet lamp are conveniently arranged for, simultaneous treatment of one and the same subject. However, by inserting an extension cord between socket 6b and the heater unit, the ultra-violet lamp and the infra-red heater may be used simultaneously for treating different portions of the same subject, or for treating different subjects in different locations at the same time.

It is apparent that my invention may be varied in detail from the arrangement specifically illustrated and described in this application. For example, it is obvious that the electrodes 3, 4 and 5 may assume various forms and be located in various special relations without departing from the essence of my invention. It is also apparent that the ballast resistance 8 may be wound upon a section of the .core of the infra-red unit 9 and serve a dual function of a ballast resistance and an infra-red heater. The necessary changes in structure of the heater unit will be apparent to one skilled in the art. For example, the unit may be provided with an annular ring concentric with the screw plug in the same manner as ring 7 on the ultra-violet lamp, one terminal of the ballast resistance being connected to the center contact button of the screw plug and the other being connected to the annular conducting ring. The socket element 6 would also be provided with a double spring contact for completing an electrical connection between the annular ring on the lamp and the annular ring on the heater. It is also apparent that ballast resistance 8 may be mounted upon the ultra-violet lamp instead of being mounted upon the double socket element 6 as shown in Figure 1.

. It will be understood that the doublesocket 6 is screwed directly into a lamp socket on the ordinary house lighting system, indicated at 11, and the lamp and heater begin operation immediately, without any special starting devices.

What I claim is:

1. An ultra-violet lamp comprising an envelope of material transparent to ultra-violet radiation, a pair of spaced electrodes sealed within said envelope, a filament bridging said electrodes, and a third electrode sealed within said envelope in spaced relation to said pair of electrodes.

2. An ultra-violet lamp comprising an envelope of material transparent to ultraviolet radiations, a pair of spaced electrodes sealed within said envelope, a filament connected between said electrodes at a point removed from the discharge terminals of said electrodes, a third electrode sealed within said envelope in spaced relation with said pair of electrodes, and a drop of mercury contained within said envelope.

3. An ultra-violet lamp comprising an envelope of material transparent to ultraviolet radiation, a re-entrant stem on said envelope, a pair of spaced parallel electrodes sealed in said stem and extending into said envelope, :1. filament connected between said electrodes at a point adjacent the stem, an extension on said stem extending beyond the ends of said pair of electrodes, a third electrode sealed within said extension and arranged in spaced relation with said pair of electrodes, and a drop of mercury contained within said envelope.

4. An ultra-violet lamp comprising an envelope of material transparent to ultraviolet radiation, said envelope containing mercury vapor at a reduced pressure, a pair of spaced electrodes sealed in said envelo e for establishing a discharge within sald lamp, a filament in said envelope, and a common source of current for energizing said filament and for establishing a discharge between said electrodes.

5. An ultra-violet lamp comprising an envelope through which ultra-violet li ht may pass, a plurality of discharge e ectrodes sealed in said envelope, 2. quantity of mercury enclosed in said envelope and means for vaporizing said-mercury comprising a filament bridged directly across two of said discharge electrodes.

6. An ultra-violet lamp comprising an envelope through which ultra-violet light may pass, a pair of discharge electrodes sealed in said envelope, a quantity of mercury enclosed in said envelope out of contact with said electrodes, and means for vaporizing said mercury comprising a filament brid a am said electrodes out with said mercury.

7. An ultra-violet lamp comprisingj all;

envelope through which ultra-violet of, contact maf pass, a pair of spaced electro es 'sea ed within said envelope, 9. filament bridging said electrodes, a third electrode sealed within said envelope in spaced relation to said pair of electrodes, a source of current, and circuit connections for supplying current to said filament from said source and for establishing a discharge between said third electrode and said pair of elec trodes.

In witness whereof I afiix my signature.

PALMER H. CRAIG. 

